But it's the film's focus on the personal, rather than the political, that has made Thatcher's enemies apprehensive and her allies unhappy.

"The Iron Lady" depicts Thatcher, now 86, as a frail, elderly figure with dementia, holding imaginary conversations with her dead husband Denis (a genial Jim Broadbent) as she looks back on her life as a double outsider — both a woman and a lowly grocer's daughter in a male-dominated, patrician Conservative Party.

Streep's eerily evocative, pitch-perfect performance looks likely to earn her a 17th Academy Award nomination and possibly a third acting Oscar. But the intimacy of the movie's portrait has led some Conservatives to accuse it of being disrespectful, distasteful, even faintly idolatrous. One lawmaker has demanded a parliamentary debate, telling the House of Commons he was disturbed by the film.

"I just wonder why the filmmakers had to go so heavily on the mental illness, the dementia side, when Baroness Thatcher has had a very important life in the politics of this country and the world," said Conservative legislator Rob Wilson.

"It left me wondering about the humanity of the filmmakers who are very subtly denigrating someone who was a great prime minister."

Thatcher rarely appears in public these days, and her inner circle releases little information about her health. But her daughter Carol — sympathetically portrayed in the film by Olivia Colman — wrote about her mother's dementia in a 2008 book.

Conservative grandee Norman Tebbit, a government minister under Thatcher, also criticized the film, saying the former prime minister was nothing like the "half-hysterical, overemotional, overacting woman portrayed by Meryl Streep" — though he admitted he was basing that judgment on the movie's trailer.

The film's director rejects the criticisms, but says she's not surprised by them.

"Those two words — Margaret Thatcher — are provocative in this country," said Phyllida Lloyd, a Briton who also directed Streep in the frothy Abba musical "Mamma Mia!"

"She still has the ability to set people on one another. People think of her either as St. Margaret who saved the nation, or the she-devil who ruined the lives of millions and bred a culture of greed."

Both sides may find their conceptions challenged by the film, which opens in Australia and New Zealand on Monday, in the U.S. Dec. 30 and in Britain on Jan. 6.

"The left wing are nervous about being asked to feel compassion for someone they think they are supposed to hate," Lloyd said. "But all we are doing is making her human.

"And the right are questioning whether there is something shameful about putting her on the screen with this frailty. But that's if you feel frailty is shameful — and we don't."

Lloyd said she initially hesitated to take on such a polarizing figure. Then she read the script by Abi Morgan ("Brick Lane," ''Shame"), and "realized it was not a political film at all."

She says it is something much more subversive — a film about an elderly woman.

"If the film is political it's in wanting to put an old lady at the center of a film," she said.

That approach makes "The Iron Lady" more a character study than a political or historical drama. It touches on a handful of episodes from her 1979-1990 tenure — the 1982 Falklands War, the 1984-85 miners' strike, the 1984 IRA bombing of the Conservative Party conference hotel in which five people died, and her eventual ousting after a rebellion by browbeaten Cabinet colleagues.

But this is not a film that makes viewers feel they are learning something new about recent and well-remembered events, in the way "The Queen" did with the aftermath of Princess Diana's death.

It is, instead, a portrait of aging and regret whose depiction of personal triumph and tragedy against a backdrop of state power has Shakespearean overtones.

Streep has called the film "Lear for girls" — foundering ruler, faithful daughter, false friends — and there's also a touch of "Julius Caesar" in the story of a leader brought down by conspiring colleagues.

"It's a film about power and the loss of power," Lloyd said. "The cost of a huge life to oneself, one's family, one's colleagues" — and about how "our great strengths — conviction, certainty — can become our greatest flaws: hubris, inflexibility."

The filmmakers' approach may be a canny box office move, allowing viewers to embrace the movie whether or not they support Thatcher's politics.

Initial reactions have been good. Several critics with no love for the Iron Lady say they were moved to tears.

There have not even been the expected howls of outrage at the casting of an American in the role of a British icon.

"I think Meryl has special rights in the U.K.," Lloyd said. "And there is almost a subconscious acknowledgment that to play someone of the magnitude of Thatcher you need a megastar."

Journalist Charles Moore, who is writing Thatcher's authorized biography, predicted the movie would upset Thatcher's friends and family, but said they could take comfort in the fact that it shows her in a positive light.

"The effect of the film is to dramatize very successfully many of the things that made Lady Thatcher so remarkable," Moore said.

"It is an extraordinary story of somebody who comes from outside the establishment by sex and by class. It's a great tale of achievement, of sacrifices made and difficulties overcome."

He also thinks it marks a turning point, an end to the days when Britons had to choose sides on Thatcher — love her or hate her.

"You have to be over 40 to hate Mrs. Thatcher," Moore said. "Young people just want to know about her."

Still, some of the Thatcherite faithful say they will be staying away from the film.

"There must be something wrong with it if it's converting all these lefty women to the view that she was something rather good," said Bernard Ingham, Thatcher's long-serving press secretary.

He says that if people "want to know what Margaret Thatcher was like they shouldn't go anywhere near it."

"Meryl Streep may be a good actress," he said, "but she ain't Thatcher."